1. Field of the Invention
The present invention relates to an imaging device and an imaging method. In particular, the present invention relates to an imaging device, which has an image sensor where an organic layer serves as a photoelectric conversion section, and an imaging method therefor.
2. Description of the Related Art
In conventional cameras having mechanical diaphragms, an aperture value (F number) used when the imaging element is exposed is fixed to a single value, and thus only an image according to the aperture value can be obtained. Hence, it is difficult for conventional cameras to obtain images based on a plurality of aperture values through a single exposure operation.
JP2009-159357A proposed an imaging device in which a single microlens is provided for a plurality of pixels of the imaging element and an image is reconstructed by weighting pixel data which is obtained from the plurality of pixels. Thereby, a depth of field of a captured image is adjusted, or characteristic blurring is expressed.
JP2006-105771A proposed an imaging device that independently captures images which are obtained from rays passing through two different pupil regions of a photography lens. Thereby, it is possible to obtain a stereoscopic image through a single image capturing operation.
JP1993-130513A (JP-H05-130513A) proposed a solid-state imaging device that is capable of nondestructive reading and reads a plurality of pixel data pieces during the same or different exposure time periods. Thereby, it is possible to acquire data pieces of pixels which are read during different exposure time periods.
However, generally, an image sensor uses photodiodes having a silicon crystalline structure which is formed in a silicon substrate as a photoelectric conversion layer. In recent years, JP2011-071483A proposed an image sensor in which an organic layer serves as a photoelectric conversion section.
Further, the photoelectric conversion section formed of the organic layer of the image sensor proposed in JP2011-071483A has an absorption coefficient larger than that of the photodiodes, and therefore reduction in thickness is achieved. As a result, there are the following advantages: electric charge diffusion to adjacent pixels is small; optical color mixture and electric color mixture (crosstalk) are unlikely to occur even when an angle of rays incident onto a light receiving surface is large; and the reduction in thickness is appropriate for miniaturization of the pixel size.